Two-factor authentication (2FA) is an identity and access management security method that requires two forms of identification to access resources and data. 2FA gives businesses the ability to monitor and help safeguard their most vulnerable information and networks.
Two-factor authentication (2FA) is the foundational element of a zero trust security model. In order to protect sensitive data, you must verify that the users trying to access that data are who they say they are. 2FA is an effective way to protect against many security threats that target user passwords and accounts, such as phishing, brute-force attacks, credential exploitation and more.
So why does it matter? If a remote attacker is able to tap into your computer via your Internet connection, they can steal your password, and your second form of authentication — if both are delivered over the same channel.
Without your physical device, remote attackers can’t pretend to be you in order to gain unauthorized access to corporate networks, cloud storage, financial information, etc. stored in applications.
By integrating two-factor authentication with your applications, attackers are unable to access your accounts without possessing your physical device needed to complete the second factor.
Types of 2FA
Hardware Tokens for 2FA
Probably the oldest form of 2FA, hardware tokens are small, like a key fob, and produce a new numeric code every 30-seconds. When a user tries to access an account, they glance at the device and enter the displayed 2FA code back into the site or app. Other versions of hardware tokens automatically transfer the 2FA code when plugged into a computer’s USB port.
SMS Text-Message and Voice-based 2FA
SMS-based 2FA interacts directly with a user’s phone. After receiving a username and password, the site sends the user a unique one-time passcode (OTP) via text message. Like the hardware token process, a user must then enter the OTP back into the application before getting access. Similarly, voice-based 2FA automatically dials a user and verbally delivers the 2FA code. While not common, it’s still used in countries where smartphones are expensive, or where cell service is poor.
Software Tokens for 2FA
The most popular form of two-factor authentication (and a preferred alternative to SMS and voice) uses a software-generated time-based, one-time passcode (also called TOTP, or “soft-token”).
First, a user must download and install a free 2FA app on their smartphone or desktop. They can then use the app with any site that supports this type of authentication. At sign-in, the user first enters a username and password, and then, when prompted, they enter the code shown on the app. Like hardware tokens, the soft-token is typically valid for less than a minute. And because the code is generated and displayed on the same device, soft-tokens remove the chance of hacker interception. That’s a big concern with SMS or voice delivery methods.
Best of all, since app-based 2FA solutions are available for mobile, wearables, or desktop platforms — and even work offline — user authentication is possible just about everywhere.
Push Notification for 2FA
Rather than relying on the receipt and entry of a 2FA token, websites and apps can now send the user a push notification that an authentication attempt is taking place. The device owner simply views the details and can approve or deny access with a single touch. It’s passwordless authentication with no codes to enter, and no additional interaction required.
By having a direct and secure connection between the retailer, the 2FA service, and the device, push notification eliminates any opportunity for phishing, man-in-the-middle attacks, or unauthorized access. But it only works with an internet-connected device, one that’s able to install apps to. Also, in areas where smartphone penetration is low, or where the internet is unreliable, SMS-based 2FA may be a preferred fall-back. But where it is an option, push notifications provide a more user-friendly, more secure form of security.